Cameba



L. H. ToLHURsT.

CAMERA.

APPLICATION FILED MAY 24.1917.

Ilm WIIIIIIIIIIIIIH HIIIIIII Patented June 3 1919.

2 S EETS-SHEET l.

L. H. TOLHURST.

CAMERA.

APPLICATlON FILED MAY 24. 1917.

l 305,841 Patented June 3,1919.

2 SHEETS-SHEET 2.

nnnp

UNITED sTATEs vPATENT oEEIcE.

LOUIS H. TOLHURST, OIF LOS ANGLES, CALIFORNIA.

CAMERA.

s peeication of Letters Patent. Patented J u ne 3, 191,9.

Application led May 24, 19117. Serial No. 170,359.

To all whom t may concern.'

v Be it known that I, Louis H. ToLHURsT, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented a new made of the entire earth surface covered in the flight and a. record made on the film of the altitude, time and direction of the aeroplane for each exposure.

l am aware that it is common to take a series of photographs upon a film by intermittently moving andl stoppin such ilm and exposing thelm during t e intervals.v 0f rest.. .In such cameras, however, the period ofl rest and period of movement of the film bear a certain relation which remains constant duringe theentire taking of the picture, andis such that the length of time of exposure varies in direct proportion to the time period of film movement.

` The object of my invention is'to produce a camera which may be used for the purposes described which will take a series of images upon a film so that each succeeding image on the film contains a portion of the preceding image thereon. To accomplish this object, I vary the time period of the Vd ark intervals, that is, vthe periods between exposures, according to the altitude of the ca'mera when such exposure is made, but the time period of the exposure remains constant' regardless of lsuch` variation of the dark periods. In carrying this out fhave so constructed a camera that the altitude of the aeroplane carrying the camera automatically regulates the length ofthe dark inter'- vals between exposures. y

'It is a further object of my inventlon to mark the film used in the camera with suittime length of the dark intervals, and the marking of the film referred to. v f

Other objects and advantages will appear hereinafter from the following specification. Referring to the drawings, which are for illustrative purposes only:

Figure 1 is a diagrammatic view, partly in section, of a camera embodying a form ofmy invention.

Fig. 2 is a section on line 2-2, Fig. 1. Fig. 3 is a sectional view on line 3-3 Fig. 1, looking in the direction of the arrow.

Fig. 4 1s a diagrammatic view of a portion of the film.

Fig. 5 Vis a sectional view on line 5,-5 Fig. 1, and l Fig. 6 is a diagrammatic view illustrat'- l ing the areas covered by exposures at different altitudes of the machine carrying the camera.

11 designates a camera box having a central chamber 12 constituting a magazine chamber, an upper chamber 13 separated from the centralchamber by a wall 14, and a lower chamber 15 divided from the central chamber 12 -by a wall,or partition 16.

17 designates a loaded film magazine for unexposed-lm, and`18 designates the takeup magazine for the exposed lm, the film 19 passing througlra film gate 20 across apertures 21 and 22 formed in the wall v16 directly behind a revolving shutter 23. It

is understood that any of the' well known forms of mechanism may be used forremoving the ilm from the lloaded lm magazine 17 andwinding the film on the take-up magazine '18 after the same has been exposed. The shutter 23 is mounted on a shaft 26 upon which is secured a gear 27 which meshes with a gear 28 securedto a 'shaft 29, the shaft 29 being driven, by means able markings to denote the timeWllen thej exposure ismade', the' altitudeat which 'the exposure is made, and the direction inw-h ioh thev machine carrying the' camera is moving at the'timeof the exposure. 1

It is afurther object of my ,inventionmake a camera of theclass whiclifj 0f is automatic action with respect toftlie 37 which'l 'enga of any suitable motive power, such as clock mechanism diagrammatically illustrated at Y 30. Secured to the shaft 26 is a single .tooth ratchet wheeI 32,- the tooth '33 of which'is adapted to be engaged byA a pawl "34`formed ona rod A35, which rod 35 is slid-V ably'mounted in' bearings 36, the pawl 34 elastically held against the face of the ratchet wheel 32 by means of a coil spring a collar 38 secured to the T35', the spr-mg 37 acting against one of tli or supports 36,. as clearly .'1 ofthe drawing.- The outer the`rod-35 is turned upwardly,` as

' 41 formed on the. periphery or face of a crank disk 42. Pivotally connected to the crank disk 42 is a crank arm 43 which is pivotally connected at 44 to the. end off a piston rod 45 secured to a piston 46 which is adapted to reciprocate in a cylinder 47.' The closed end 48 of the cylinder 47 is con- `10 nectedby' means of a pipe 49 with a needle valve 50,` a pipe 51 connecting the valve 50 with a tank or reservoir 52 adapted to hold a fluid, preferably Ialcohol, for the purposes hereinafter referred to, it being understood that air or liquid may be used. A needle or valve member 55 is pivotally connected at 5.6 to the longlend 57 of a rock arm 58, the rock arm 5 8 being pivotally connected at 59 to a link 60 which in turn is pivotally connected at 61 to the short end of -a lever 62, the long end vof the lever 62 being pivotally connected at 63 to a compensating aneroid 64. The lever 62 is slidably and pivotally connected by means of rollers 67 to a slidable frameV 68 mounted in any suitable manner upon the frame of the camera, such frame '68 being adjustable by means of a screw 69 which extends through the frame.

- 68, one end of the screw being rotatably mounted ina bracketC 70 and the `opposite end of the screw having a knurled head 71 which extends through an opening 72 in the Wall of the camera, so that the same may be operated from the exterior of the camera. The short arm 75 of the rock arm 58 is pivotally connected at 76 to an aneroid barometer 77; The crank disk 42 is operated through the medium of a bevel gear 80 secured to a shaft 81 upon which the crank disk 42 is mounted, the gear 80 being driven by means of a similar gear 82 mounted on a shaft 83, the shaft'83 havinga bevel gear 84 at its opposite end which meshes with and is driven by a bevel gear 85 mounted lupon a shaft 86 driven by means of a train of gears 87 from a driving source which, in the present instance, is diagrammatically'illustrated at 88 as a coil spring.

Secured to the shaft 86 is a disk 90 which is pivotally connected by means of a pin 91 to claws 92, which are provided with-{ingers 93, extending into the -perforations along the edge of the film for the purpose of moving the film, such portion of the mechanism being any of the Well vknown .forms used in motion picture cameras.

Mountedv on the lower wall 97 of the camera is a lens box 98 having therein a.

suitablelens 99 which lies in the optical axis of the aperture 21, it being understood that the lensV 99 is permanently fixed so that it remains constantly in universal focus with the film 19. c

A100 designates a housing or case which extends across the bottom of the camera, as

clock 104. The housing 100 above the glass plate 101 is provided with a series of openings'llO through which light is permitted to strike the dials of the respective instruments, the light from the faces of which is reflected successively through prisms 112, a lens- 113, prisms 114, through the aperture 115 in the shutter, and through' the Y aperture 22 in the wall 16 against the ilm exposed 4through the aperture 22, such reiiected image following the course diagrammatically illustrated by the dottedline 120 in Fig. 1.'

The camera is used in the following manner:

The camera is hung in suitable mechanism uponl the aeroplane with the lens 99 pointing vertically downward, as shown in Fig.

1 of the drawings, the camera being suitably mounted and weighted as will be 'readily understood by any one skilled 'in A'the art, so that'regardless of the pitch or angle o'f the aeroplane the optical axis of the camera remains perpendicular at all vIt is essentialthat the needle 55 of the valve 50 be in the Same position at the commencement of each flight ofthe machine, regardless of atmospheric conditions, which adjustment is made by the com nsating action ofthe aneroids 64 and 7:? acting through the rock arm 58, link 60 and lever 62, and when such adjustment is madeA set screws 65 and 66 are brought into contact with the lever 62, after which the aneroid 77 controls the operation of the needle 55 during the flight, as hereinafter referred to.

As the aeroplane leaves the ground., the

motor 88 is started in motion, and through the medium of the train of gears 87 and shaft 83 the crank disk 42 is driven in the direction of the arrow shown in Fig. 1. The speed of .movement of the crankvdisk is regulated against the driving mechanism just referred to by'means of the piston 46'reciprocating in the cylinder 47'v against the fluid therein passing through the valve 50, the passage ofthe iuid through the valve 50 being conv trolled by the position lof'jthe needle 55 which is controlled bv means of the aneroid 77 through the mechanism heretofore described. Such mechanism operates the needle 5 5 to approach the valve seat 121 as the aeroplane rises to a higher altitude, thereby restricting the flow of iluid to the valveand consequently causing a slower move"- ment of the piston 46 in the cylinder 47, it

isc i being understood that the needle 55 at lower altitude isffarther away from its seat 121, thereby permitting a freer passage of the fluid through the valve and a freer or quicker movement of the piston 46, in the A lcylinder 47, thereby controlling the speed are indicated at K, L, M and of rotation of the crank disk 42 and consequently the length of time between exposures. v

As the crank disk 42 rotates, the tooth 41 engages the finger 40 on the rod 35 thereby moving the rod to, disengage the pawl 34 from the tooth'33 on the ratchet wheel 32, thereby permitting movement of the shaft 26 and a rotation of the shutter 23 to expose the lm. As soon as the tooth 41 passes the finger 40, the rod 35 is immediately moved by the action of the spring` 37, so that the pawl 34 comes into engagement with the face ofthe ratchet 'wheel 32 and-catches the tooth 33 thereon, retaining the saine and arresting movement of the shutter until the tooth 41 has made an eri-Q` tire revolution and again come in contact with the finger 40`v when the operation is repeated. During the movement of the crank disk 42, after the tooth has passed the finger 40, and until the tooth 41 again engages theJ nger40, the claws 92 are operated through the train of gears ..87 .to move the film, and during such movement it is understood that the shutter 23 covers the apertures 21 and 22 inthe wall 16. During the instant of exposure it is understood 'that the aperture 115 in the shutter causes the image from the lens 99 and lens 113 to be projected through the apertures 21 and 22 respectively in the wall y16 onto the film 19, the result being a series of exposures a upon the film 19, having between each exposure ai an exposurge b made through the aperture 22, the exposure a being a negative image of the ground within the optical field of the lens 99, and the exposure b being a negative of the dials of the compass, the aneroid, and clock', at the instant the exposure ai is made.

The length of the area of the earths sur-:.1- face included in each exposure is illustrated in Fig. 6, the aeroplane indicated at 200,-

-being shown diagrammatically at different elevations,n and the lines e indicating the' angle boundaryl of the optical feldof'the, camera atthe various heights indicated.v

Assuming ythat the aeroplane is traveling' in the direction of the arrow shown in Fig. 6, four positions of the aeropjlane in vflight respectively, the earths surface by al line O, and sea level by the base line P.'l u Y The aeroplane in positions K and L is at 4the same altitude and the intervals between exposures is the same; lAs ythe vaeroplane reaches'the' position indicated at M the aeroplane is ata 'higher altitude than whenat vthe camera. A

the time between' the ex- L. Consequentl (17M has increased, as indiposure at L an catedv by the increase in distance between the positions L and M. The same applies to the positions M and N as just described with relation to the positions indicated at M and L.v It is to be noted that theangle boundary lines e of each position overlap, as indicated at R, so that each succeeding negative bears a portion indicated at S shown on the preceding negative.

As each exposure is made it is understood that the dials of the clock 104, compass 102 .and aneroid 103 are photographed on the negative and a 'record made on the film showing the altitude at'the time of exposure.

VThe time the exposure is made,z and the direction of travel of the aeroplane, when taken together in connection with vthe. photographed earths surface, forni a continuous record and picture of the flight.

I claim asmy invention 1. In a camera for air craft, film guiding means, means for intermittently moving the film, means for intermittently exposing successive portions of the film, and fluid means for automatically varying the length of the ltime intervals betweenexposures according to the altitude of the camera. f

2. In a camera for air craft, film guiding means, exposing means for successively exposing portions of the film, a. barometer, and

means operated by the barometer adapted vary the time intervals between exposures.

I3. lIn afcamera for air craft, film guiding means, a shutter, operating means for thek shutter, means for arrestin movement of the shutter, means for releasing said arrest- 1 ing means to permit'the shutter to expose the film, a barometer, means operated by the barometer adapted to time the action of the the camera, and means for between exposures.

4. In a camera for air craft, film guide means, an aperture plate, a shutter, means4 moving the film for operating the shutterto expose the film,

means for arresting the movement of the shutter to cause dark intervals between ex- .posuresmeans forc releasing'said arresting means, means for operating said releasing l means, braking means for fsaid operating means, a barometer and means operated by said'barometer for va g the action of the braking means according to the altitude of 5. In a camera for air craft, film guide means, a wall having an aperture therein, a'

.shutter infront ofsaid aperture, means for -a uid cylinder, a piston in said cylinder connected to thedriving means, a resreleasing means according to'the altitude of ervoir, connections between said reservoir and the cylinder valve means for controL ling the flow of der from the reservoir, and a barometer conf neeted to said valve adapted to operate the same. f

6. In a camera for ai'r craft, film guide means, a wallhaving an aperture therein, a

shutter, means for rotating the shutter, a fluid cylinder, a piston therein, a Huid reservoir; a connection between said reservoir and cylinder, a valve in said connection,

barometric controlling mea-nsforsaid valve, releasing means forsaid shutter, and means for connec'tlng sald piston to said releaslng .7. In a camera for air craft, ilm guide means, means for-.intermittently moving the film, a shutter arranged to expose the film between the intervals of movement "of the same, means for throwing aphotographic image of an object on the film and simultaneously making a photographic image on the film of identifying data, vand means for varying thetime between exposures, said means consisting of shutter releasing mechanism,

' motive means for operating said releasing mechanism, means for varying the speed of said m0tiveIm'eans',-said :last named means fluid from and to the cylincraft from the ground;

consisting of Huid regulating means, andl barometric means for controlling said iuid means. p

8. -In a camera for air craft, film guiding means, exposing means for successively exposing portions of the ilm, a. barometer,

means operated by the barometer adapted means for projecting the image of an object l on the film between exposuijes,'and means for regulating the operation of the shutter to time the exposures so that a portion of image regardless of the height of the air In testimony whereof t my hand'k at Los eles, California, this 17th dayof May, 191

LOUIS H. roLHUesfnv I have hereunto set- 55 each image appearsv m the next successive 

